#693)

# Description

In [This commit that landed in
v0.48.0](Kludex/starlette@40a8147)
starlette changed constants to conform to
[RFC9110](https://www.rfc-editor.org/rfc/rfc9110#name-413-content-too-large).

It's the only [one
affected](Kludex/starlette@40a8147#diff-966c562bff3b11736a75544f42526c942c185b9fe9eb4b7f5a0dabbeca874fa7R180)
that I could find in this codebase.


- [x] Follow the [`CONTRIBUTING`
Guide](https://github.com/a2aproject/a2a-python/blob/main/CONTRIBUTING.md).
- [x] Make your Pull Request title in the
<https://www.conventionalcommits.org/> specification.
- Important Prefixes for
[release-please](https://github.com/googleapis/release-please):
- `fix:` which represents bug fixes, and correlates to a
[SemVer](https://semver.org/) patch.
- `feat:` represents a new feature, and correlates to a SemVer minor.
- `feat!:`, or `fix!:`, `refactor!:`, etc., which represent a breaking
change (indicated by the `!`) and will result in a SemVer major.
- [x] Ensure the tests and linter pass (Run `bash scripts/format.sh`
from the repository root to format)
- [x] Appropriate docs were updated (if necessary)

# Tests
```zsh
uv sync --all-groups
```
Before and after: confirmed that this is fixed.
```zsh
uv run python -W error::DeprecationWarning -c "from a2a.server.apps.jsonrpc.fastapi_app import *"   
```
Confirmed that tests worked with
```zsh
uv run pytest
```

# Other
uv.lock currently has 

```toml
[[package]]
name = "starlette"
version = "0.50.0"
```
So I don't think the dependency pinning is a breaking change.

---------

Co-authored-by: Holt Skinner <13262395+holtskinner@users.noreply.github.com>

# Description

Thank you for opening a Pull Request!
Before submitting your PR, there are a few things you can do to make
sure it goes smoothly:

- [x] Follow the [`CONTRIBUTING`
Guide](https://github.com/a2aproject/a2a-python/blob/main/CONTRIBUTING.md).
- [x] Make your Pull Request title in the
<https://www.conventionalcommits.org/> specification.
- Important Prefixes for
[release-please](https://github.com/googleapis/release-please):
- `fix:` which represents bug fixes, and correlates to a
[SemVer](https://semver.org/) patch.
- `feat:` represents a new feature, and correlates to a SemVer minor.
- `feat!:`, or `fix!:`, `refactor!:`, etc., which represent a breaking
change (indicated by the `!`) and will result in a SemVer major.
- [x] Ensure the tests and linter pass (Run `bash scripts/format.sh`
from the repository root to format)
- [x] Appropriate docs were updated (if necessary)

Fixes #692 🦕

## Problem

`_clean_empty` uses a truthiness check (`if v`) that drops legitimate
falsy values like `0`, `False`, and `0.0` alongside the intended empties
(`''`, `[]`, `{}`).

This affects `canonicalize_agent_card()` — the only caller — which
produces canonical JSON for signature verification (RFC 8785). An
`AgentCard` with e.g. `AgentCapabilities(streaming=False)` would have
the field silently stripped, losing the distinction between "explicitly
disabled" and "unspecified".

## Fix

Restructured `_clean_empty` so that only empty strings are converted to
`None` at the leaf level, and empty containers collapse naturally via
`or None` after their children are cleaned. The filter becomes `if v is
not None`, which only catches values the function itself converted —
`0`, `False`, and `0.0` never go through any conversion and flow through
unchanged.

### Alternatives considered

If maintainers prefer a different style, happy to switch to either:

- Inline sentinel: `if v not in (None, '', [], {})` directly in the
comprehensions, keeping the original structure with a fixed filter.
- Helper predicate: extract an `_is_empty(v)` function and use `if not
_is_empty(v)` as the filter in both dict and list comprehensions.

## Tests

Parametrized tests covering empty removal, falsy value preservation,
mixed cases, non-mutation, and a regression test confirming
`streaming=False` survives in `canonicalize_agent_card` output. Happy to
trim test cases if seen as excessive.

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

🤖 I have created a release *beep* *boop*
---


##
[0.3.24](v0.3.23...v0.3.24)
(2026-02-20)


### Bug Fixes

* **core:** preserve legitimate falsy values in _clean_empty
([#713](#713))
([7632f55](7632f55))
* **deps:** `DeprecationWarning` on `HTTP_413_REQUEST_ENTITY_TOO_LARGE`
([#693](#693))
([9968f9c](9968f9c))

---
This PR was generated with [Release
Please](https://github.com/googleapis/release-please). See
[documentation](https://github.com/googleapis/release-please#release-please).